Genetic Testing Before You Conceive

It used to be that only couples with a family history of certain genetic disorders would seek genetic counseling before deciding to have a baby. Now with more and more women delaying motherhood until their mid 30’s to early 40’s, preconception genetic counseling has become more popular. Genetic counseling involves patient education, analyzing personal/family history, and discussing the implication of genetic testing.

The chances of having a child with a chromosomal problem increase dramatically when a pregnant woman is over 38. Preconception genetic counseling is recommended in cases where couples have suffered early pregnancy loss or other reproductive problems or where there’s a family history of certain genetic diseases. By screening couples for these genetic diseases before they conceive, it can help them understand the risks and plan accordingly.

The American Society of Reproductive Medicine (ASRM) and the American Urological Association also recommend preconception genetic testing in men with low sperm counts. Recent studies have linked this problem to possible underlying genetic disorders, such as cystic fibrosis, a condition that affects all of the glands in the body that secrete mucus and fluids leading to thick, abnormal secretions usually in the lungs and pancreas. It’s also recommended to parents who have already delivered one or more children with genetic birth defects or to couples in which one partner has a congenital defect, such as congenital heart disease.

Through its Success Through Assisted Reproductive Technologies (START) program, DVIF&G is one of only a handful of infertility practices to offer couples preimplantation genetic diagnosis (PGD), the latest technological advance in helping couples deliver healthy babies. Preimplantation genetic testing helps couples that choose in vitro fertilization (IVF) have a successful pregnancy. IVF involves combining an egg and sperm outside of the woman’s body to create an embryo that is implanted in her uterus, also known as embryo transfer (ET). PGD is a procedure where a single cell can be mechanically removed from an embryo on day three of its culture after IVF. This cell can then be tested for defective chromosomes. If the cell is determined to be normal, then the embryo from which it came can be transferred back to the patient without risk of transmitting a genetic disease.

With PGD, genetic abnormalities such as Down syndrome, and also point mutations such as cystic fibrosis, thalassemias [hereditary anemias common among people of Mediterranean descent], and Tay-Sachs disease, can be diagnosed prior to transferring an affected embryo through an IVF-ET procedure. This approach successfully avoids adverse outcomes of the pregnancy. Medical intervention and surgical treatment is therefore avoided, and a healthy child is born. The emotional relief provided to the couple is invaluable.

Since approximately 60 percent of all reproductive losses in pregnancy are linked to a chromosomal abnormality, performing this testing may help prevent unsuccessful IVF pregnancies. A recent study found the pregnancy rate with IVF patients ages 35 to 45 increased from 16 to 30 percent when preimplantation genetic diagnosis was conducted.

Jessica A. Macdonald is the supervisor of DVIF&G’s state-of-the-art Reproductive Laboratories. To contact her, please call 609-895-0088 or e-mail her at jessica@startfertility.com. For more on DVIF&G, please visit www.dvifg.com.